2006 sportsman 500 efi awd issues

Just picked up the above machine with 247hrs on it. So far I’ve replaced rear wheel bearings, both ball joints, front cv boot and stator. The issue I’m now having is that the awd light works, speedo works, but the awd will not engage. I’ve pulled the connector to check for 12v but it only fluctuates between 6-9v which leads me to believe I have a bad ground. If I hook 12v directly into the front diff, it still doesn’t engage. I’m about to start pulling the front diff to tear into it but was wondering if anyone knew where I should look for the bad ground(so I don’t have to run a new ground) and what else I should look for once I get the diff pulled. The input shaft is pretty sloppy so I will pick up a rebuild kit.